Horizontal sweep transformer



Oct. 11, 1960 D. H. HARSE 2,956,250

HORIZONTAL SWEEP TRANSFORMER Filed May 31, 1955 INVENTORI DOUGLAS H.HARSE,

QMK

HIS ATTORNEY.

United States, Patent HORIZONTAL SWEEP TRANSFORMER Douglas H. Harse,North Syracuse, N.Y., assignor to General Electric Company, acorporation of New York Filed May 31, 1955, Ser. No. 512,134

7 Claims. (Cl. 336-192) This invention relates to the art of highvoltage transformers suitable for use in television receivers to providea high accelerating and deflection voltages required by suchinstruments.

Deflection transformers usually found in television receivers include aplurality of closely coupled coils superimposed one over the other.These coils are wound on a leg of a core which is generally rectangularin configuration and open at the center to provide a window. The coilsin standard practice may number three. The first, a primary winding, isof the elongated solenoidal type and generally extends along almost theentire length of the leg on which it is placed. A secondary coil isclosely coupled thereto and is in fact usually situated within theopening of the primary coil. These two coils are of similarconfiguration and are separated only by a suitable insulating material.-A tertiary winding is provided around the primary, separated only bysuitable insulation. The secondary coil, which may be a tapped windingof the primary, functions to supply voltage for the deflection yoke,encompassing the cathode ray tube, While the tertiary coil provides theaccelerating voltage for the anode of the tube. The entire transformeris usually mounted in a rigid metal assembly for supporting andretaining purposes and terminals for the coil leads are provided on thissupporting frame. In standard practice this unit, both the transformerand its frame, are mounted in a metallic container for shielding andfire-proofing purposes. Additional windings sometimes surround a portionof the core to provide a voltage for filament heating circuits. Such aconstruction is inherently difficult to adapt to mass productiontechniques as the assembly involves a considerable number of parts andsteps. The terminals of the coils must be provided on the frame and,since there is a high voltage present, location and insulation of all ofthe coil elements is a problem.

An additional feature of those transformers used for this purpose hasbeen the use of either a laminated iron core or a core formed from aferrite material molded into a desired shape. The legs, forming a partof this core are rectangular in cross section. Since the coils Woundthereon are, as pointed out, solenoidal or circular in cross section,the maximum effective coupling between the coils and the core has notbeen obtained. It would therefore be advantageous to provide atransformer which was inherently amenable to the application of massproduction techniques, which provides facilities for the connection ofall of the circuits associated with a television sweep transformer andwhich achieves the optimum coupling between the coils and the corethereof.

Therefore, it is an object of this invention to provide a novel highvoltage transformer having a core which is relatively simple inconstruction and consequently may be easily assembled and disassembled.

It is another object of this invention to. provide a novel. transformerwherein means is provided for making connections to the windings thereofin such a manner 2,956,250 Patented Oct. 11, 1960 ice that theinsulating and locating problem associated with high voltagetransformers is considerably diminished.

It is still another object of this invention to provide a noveltransformer wherein the coil form on which the transformer windings arewound and the cooperating and supporting element of the core have thesame crosssectional configuation so that the optimum coupling isachieved between the coils and the core.

It is a further object of this invention to provide a novel transformercoil form and terminal holder or circuit element support means formedfrom a single piece of material so that the cost of these two componentsand their assembly to the transformer unit is reduced.

It is still a further object of this invention to provide a noveltransformer including a core wherein the structure holding thetransformer in its assembled position is considerably simplified so thata cumbersome, weighty means is not required to mount the transformer inits assembled position on the chassis of the television receiverutilizing such an element.

In carrying out my invention, in one form thereof, I provide atransformer core of ferrite magnetic material which consists of twosubstantially U shaped sections molded to the desired shape. 'Thesections are placed in a position wherein the legs of the Us confronteach other so that a rectangular structure is formed with a window.Encompassing one set of legs is a circuit element support formed of aninsulating material. One portion of the circuit element support isformed as a tubular piece and substantially surrounds one set of legs.The required coils are wound thereon. The legs are circular incross-section to match the tubular portion of the circuit elementsupport whereby maximum coupling between the windings and the core canbe achieved. The end portion of the circuit element support is formed asa disc greater in diameter than the tubular portion. Adjacent the outerperiphery of the disc portion I pro vide electrical connectors to whichthe coil leads may be attached as desired. The U sections forming thetransformer core each has a groove formed on the outer side of the legsthereof. When placed in an assembled position, the grooves of each setof legs match and a fastening means such as a U bolt encompassing theentire transformer may be passed through the grooves and the entireassembly thereby secured in its proper position. This unit whenassembled may be attached to a suitable mounting means and placed in ametallic shield, or, if desired, the unit may be attached directly tothe wall of such a shield. By the use of this construction, I achieve areduction in the number of parts, simplicity in the assembly, andgreater efiiciency of operation.

Further objects and advantages of my invention will become apparent asthe following description proceeds, reference being had to theaccompanying drawing, and its scope will be pointed out in the appendedclaims.

Figure l is a side view of an assembled transformer embodying myinvention;

Figure 2 is an end view of the transformer illustrated in Fig. l; and

Figure 3 is an exploded view in perspective of the elements of thetransformer embodying my invention.

Referring now to Figure 1 of the drawing there may be seen a transformerdesignated by reference numeral 1. The transformer is mounted on aportion of a shielding wall or other suitable support 2. A pair ofU-shaped sections 3 and 4 which are molded out of a ferrite or othersuitable magnetic material are assembled so that the legs of oneU-shaped section confront and abut the legs of another U-shaped section.When so assembled they form a rectangular structure which presents awindow 5. In order to hold the transformer in its assembled position, aU bolt 6 may be provided. The bolt has a pair of legs 7 which arethreaded at their ends and extend through matching grooves 8, shown inFigure 3, in the core legs 3 and 4. The legs 7 of the U bolt 6 may bepassed through apertures provided in the support 2 and the entiretransformer unit 1 retained in its assembled position by means of thenuts 9. A circuit element support which functions as a coil form andinsulator encompasses one pair of core legs. A first or hollow tubularportion 10 of the circuit element support surrounds a pair of abuttingcore legs and formed integrallytherewith is a second or enlarged discportion 11. Reinforcing ridges 11 may be formed to extend from thetubular portion 10 to the disc 11 for strengthening purposes and tomaintain separation of the coil leads. Formed in the periphery of thedisc portion 11 are a plurality of slots 12 to receive the transformercoil leads in a manner to be described in greater detail hereinafter.Metallic electrical connectors or terminals such as shown as 13 may bemounted in the disc portion by being molded therein or retained by asuitable mechanical connection. The disc portion 11 is provided with apair of downwardly depending portions 14 which when the circuit elementsupport is assembled on the core legs overlie either side of a verticalsection of the core section 4 so that relative movement between thecircuit element support and the transformer core is prevented. Ifdesired, suitable strengthening projections such as shown at 15 on thedisc portion 11 may be provided.

Any desired windings may be provided on the tubular portion 10. Thewindings illustrated in the drawing are typical of those presently inuse. They are constituted by a solenoidal-type winding 16 which has apancake-type winding 17 superimposed directly thereover and separatedtherefrom by suitable electrical insulation (not shown). Furtherinsulation which may be a molded rubber or wax cover 18 is providedaround the periphery of the pancake winding 17. A plurality of leads 19extend from the windings on the tubular portion 10 of the circuitelement support between the ridges 11' and are passed through the slots12 and connected to the electrical terminals 13. It is obvious that anynumber of slots 12, electrical terminals 13 and leads 19 may beprovided.

In the assembly of the transformer, the tubular portion 10, after coils16 and 17 are wound thereon, is inserted over one of the legs of theU-shaped core section. The other U-shaped core section 4 is now insertedinto the open end of the tubular portion 10 so that the downwardlydepending portions 14 of the disc 11 encompass each side of the verticalportion of the core section 4. The legs of the U-shaped bolt are passedthrough the matched grooves 8 of each pair of core legs and the entireunit is mounted on the support 2 by means of the nuts 9.

It may be seen that the above-described transformer is capable of rapidassembly. It may further be seen that the circuit element support whichconstitutes the coil insulator, may be fabricated rapidly andinexpensively out of any suitable insulating material; for instance, bymolding a plastic. The electrical terminals 13 provided on the discportion 11 are spaced a distance apart and the leads 19 extend betweenthe ridges 11 so that the problem of insulating the leads isconsiderably lessened.

Further, the enlarged disc portion 11 increases the number of connectorsand leads which can be handled on the terminal. The entire unit iscapable of rapid assembly and is particularly adapted to take advantageof mass production techniques. The legs of the U-shaped core sections 3and 4 which are circular in cross section, match the tubular portion 10which is also circular in cross section and a much more effectiveelectrical coupling is thereby achieved between the coils 16 and 17 andthe core sections 3 and 4. While I have shown a particular embodiment ofmy invention, it will of course, be understood that I do not Wish to belimited thereto since various modifications both in the circuit elementsupport,

4 the means of mounting the unit may be made and I contemplate by theappended claims to cover any such modifications as fall within the truespirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A transformer comprising a plurality of coils superimposed one overthe other, a core having a leg extending through the opening of theinner-most coil, a circuit element support formed from an insulatingmaterial, said circuit element support including a tubular portionencompassing said leg and interposed between said leg and the inner-mostcoil, said circuit element support including a disc portion having awidth greater than the width of said tubular portion, and electricalterminals mounted in said disc port n adjacent the periphery thereof andadapted to have leads extending from said coils coupled thereto.

2. A transformer as defined in claim 1 wherein said core is formed oftwo substantially U-shaped sections positioned so that one leg of eachsection abuts a leg of another section to present a substantiallyrectangular configuration.

3. A transformer as defined in claim 2 wherein the tubular portion ofsaid circuit element support encompasses a pair of the abutting legs andthe disc portion of the circuit element support has portions defining anopening encompassing a vertical portion of one of said core sections.

4. A transformer comprising a pair of U-shaped core sections, the legsof said sections being circular in cross section, one leg of eachsection being placed in confronting relationship to a leg of the othersection so that a core having a rectangular configuration with a windowtherein is formed, a plurality of closely coupled coils superimposed oneover the other surrounding one of said pairs of legs, a circuit elementsupport including a tubular portion being circular in cross sectionsurrounding said one pair of said legs and being interposed between theinnermost coil and said one pair of legs, said tubular portion and saidlegs permitting .close electrical coupling of said coils and said core,said circuit element support having enlarged disc portion formedintegrally with said tubular portion, the largest diameter of said discportion being greater than the diameter of said tubular portion, aplurality of electrical terminals mounted in said disc portion adjacentthe outer periphery thereof, a plurality of coil leads attached to saidelectrical terminals and extending along said disc portion to saidcoils, said disc portion having a pair of depending portions formedthereon and spaced apart presenting a cutout into which a verticalportion of one of said U-shaped core sections fits whereby the movementof said circuit element support and said coils relative to said core islimited.

5. A transformer comprising a hollow circuit element support having abody portion and an enlarged disc portion formed integrally with andhaving a greater diameter than said body portion, a plurality ofelectrical terminals mounted in said disc portion, a plurality ofclosely coupled coils superimposed one over the other mounted on thebody'portion of said hollow circuit element support, said coils betweenconnected to said electrical terminals on said disc portion, a pair ofU-shaped core sections having slotted legs, one leg of each core sectionaligned in confronting relationship to a leg of the other core sectionwith the slots in said legs aligned to form a rectangular shaped corewith a window therein, said circuit support element being mounted on onepair of said legs,- a U-shaped bolt mounted in said slots, and meansattached to said U-shaped bolt for holding the parts of said transformertogether.

6. A transformer comprising a plurality of closely coupled coils, afirst and second U-shaped core section, the legs' of'said core sectionsbeing circular in crosssection, one leg of one section disposed inconfronting relationship to a leg of the other section whereby a substantially rectangle configuration is formed, each of said legs having agroove formed therein, the grooves in said legs being aligned when theaforesaid rectangle configuration is formed, fastening means passingthrough said grooves for holding said U-shaped core sections in theirassembled positions, a circuit element support formed of an insulatingmaterial having a circular cross-section on at least a portion thereof,the circular cross-section of said circuit element support carrying saidclosely coupled coils and encompassing one of said legs of circularcross-section thereby providing close coupling between said coils andcore.

7. A transformer comprising a core of magnetic material having a pair ofU-shaped core sections with the legs of said core sections beingcircular in cross-sectionhaving grooves therein, the legs of said coresections positioned in confronting relationship with the grooves thereinaligned to form a rectangular core, a circuit element support having aportion thereof of circular cross-section mounted on one pair ofabutting leg portions of said core, a plurality of coils mounted on thecircular cross-section portion of said circuit element, support therebyproviding close coupling between said coils and said core, a U- shapedelement having the legs thereof positioned in the aligned grooves ofsaid core, and means coupled to said U-shaped element for holding saidtransformer together.

References Cited in the file of this patent UNITED STATES PATENTS2,288,201 Meyerhans June 30, 1942 2,494,350 Mittermaier Jan. 10, 19502,500,766 Chert et a1. Mar. 14, 1950 2,544,658 Dentremont Mar. 13, 19512,612,545 Gray Sept. 30, 1952 2,678,413 Adler et a1. May 11, 19542,702,375 Johnson Feb. 15, 1955 2,800,620 Ebbeler et al July 23, 1957

